Calculations of lightmapping, bake are done in the GPU or only in the CPU?

Hello,

When Unity is performing calculations with Light on static objects to create the light maps, does it use the graphic card or does it only use the CPU?

I need to know this to make good use and choose the correct computer.

Thank you very much for your attention

Depends on the options you select for baking lightmaps.
“Enlighten” is mostly (entirely?) CPU baking.
“Progressive CPU” is CPU only baking.
“Progressive GPU (preview)” is GPU baking, but may have some bugs and I believe is still missing some features that the other two options support.

There’s also Bakery on the asset store, which is GPU based lightmap baking with much better quality, but is also missing some features the built-in baking has.

Thank you very much for your response now I can guide my choice.